Control system for internal-combustion engines.



F. PURDY.

CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION HLED DEC. 18. 1911. RENEwED luNE 25.1915.

` l ,l 86,037. Patented Jun@ 6, 1916.

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F. PURDY.

CONTROL SYSTEM FOR INTERNAL cONIBUsTlON ENGINES.

RENEwED JUNE 25.1915.

APPLICATION FILED DEC. 18| 1911.

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Patented June 6, 1916.

UETTED sTATEs PATENT oEEToE.

FREDERICK PURDY, OF KENOSHA, WISCONSIN, ASSIGNOR ONEHALFTO FORE BAIN', LA GRANGE, ILLINOIS.

l CONTROL SYSTEM FOR INTERNAIFCOMBUSTION ENGINES.

Specification of Letters Patent.

Patented June 6, 1916.

Application led December 18, `1911, Serial No. 666,324. Renewed June 25, 1915. Serial No. 36,411.

To aZZ whom vit may concern:

Be it known that I, FREDERICK Prnnr, a citizen of the Inited States. residing at Kenosha. in the county of Kenosha and State of lYisconsin. have invented certain new and useful Improvements in Control Systems for Internal-Combustion Engines, of which the following is a specification.

The general object of my invention is to provide means for ilnproving the operation and eiiciency of internal combustion engines wherein the ignition-time is controllable and the fuel supply is regulable.-as is the case in the modern gas engine, equipped with the ordinary throttle and with electrical sparking appliances.

In the following description I will for succinctness use the term spark as indi-V cating an ignition agent variable in timing. and the term throttle as meaning any suitable means for regulation of the fuel supply.

Mv invention consists in novel means of ignition-time control for such internal combustion engines: in novel means of regulation of the charge-volume: in the cordination of a charge regulating means with an i-gnition-time controlling means; and in provision for the automatic governing of the controlling instrumentalities.

In the operationof an internal combustion engine. an appreciable interval of time is required for the propagation of the flame in an explosive mixture of given volume, such time varying. roughly speaking, inversely with fuel density` so to term the relative number of combustible particles per unit of volume in the compressed charge.- and also inversely with the density of the air in which the particles are suspended. lith a given richness of mixture (within working limits. of course), the time moment of fiame propagation varies, therefore, generallyinversely in accordance with the compression of the charge, by reason of the effect of'compression variations upon both the fuel density and the air density. And with constant compression, the time moment of iame propagation varies. of course, generally inversely with the richness of the mixtuie and the consequent variations of fuel density,

In the operation of the modern gas engine,

it is customary to advance the sparkthat is, to cause the ignition spark to be made before the engine piston reaches the end of its compression stroke,-and to vary the -advance or lead of the spark generally in accordance with the engine speed varlations. in order that the working pressure in eecting its rapid rise due to combustion may be most eilicient-ly applied substantially as the 'engine crank passes dead center and the piston starts on its working stroke. Generally speaking, therefore, the faster the engine runs, the farther the spark must be advanced, for during a given time interval of Hallie propagation the crank will travel through a greater angle at high speed than at low speed. yThis variation of the spark time, if it is to be directly proportional to the engine speed, may be effected by a suitable speed-responsive device, actuated by the engine a-nd controlling appropriate spark-initiating or spark-distributing mechanism.

I have found. however, that spark-time' control by a lnere engine speed-responsive device. as above suggested, does not fulfil all requirements ofautomatic spark-time regulation for most efficient and economical operation of the engine.

In the operation of the ordinary gas engine, when a light load is being carried, the engine is throttled to a greater or less extent, and a smaller charge is drawn int-o the engine cylinder than is the case Where the engine is working under a heavy load and the fuel supply conduit is correspondingly more fully opened. Consequently, there is a smaller volume of gaseous fuel to compress and a lower compression under the light load than under the heavy load effected by the speed-responsive device, should be made in harmony with the adjustment of the throttle or other fuel-regugine is running under a constant load, in-

crease of the engine speed tends to result in decrease of the fuel density and compression as the quantity of the fuel drawn into the cylinder against the resistance of the carbureter and the throttle is less than when the engine is running slowly.

To meet the requirements for efficient spark-timing in a. throttle-controlled engine, imposed by these underlying considerations, I provide time-regulating means for the spark which is under the control, jointly, of an engine speed-responsive device and of the fuel-regulating device or throttle. so that the tendency of the speed-responsive device to advance or retract the spark accordingly as the engine s eed is increased or ydecreased will be modi ed by the compensating adjustment for advancement or retraction of the spark accordingly as the throttle-valve opening is decreased or increased in size.

It may Valso be deemed advantageous in the operation of a gas engine to maintain a uniform critical compression, as nearly as possible, at all engine speeds, and it is therefore advantageous so to regulate the chargevolume by the introduction of air into the engine cylinder that the charge volume (and therefore the compression) may tend to remain uniform under different speed conditions and throttle adjustments. Therefore` as a matter of advantage per se, as well as conjointly with the spark-time control, I make provision of a charge-regulating means comprising a valve for admitting `air to the engine cylinders (preferably locating the valve in the fuel passage between the throttle and engine), said valve being regulable by the action of an engine-speed-responsive device, preferably modified by the action of the device responsive to the throttle adjustment.

It will be apparent thatl Where the spark advances in accordance with the increases in engine speed and further in accordance with decreases in the throttle area, the spark will be further advanced when the engine is running under light load (with relatively closed throttle) at a gii-'en speed than when the engine is running under heavy load (with relatively open throttle) at the same speed. Then the engine is running at slow speed under heavy load, boththe wide opening of the throttle and the slow speed of the engine tend jointly to cause retraction of the spark and when the engine is running under light load at high speed, the controlling actions of both the throttle and speed-responsive means jointly tend to produce advance of the spark. In shortf-the spark-time is regulated in harmony jointly with the speed of the engine and with the condition of the fuel control means, which governs primarily the fuel density.

The regulation of the auxiliary air component of the charge in harmony with the speed of the engine and preferably with the condition of the throttle, tends to the production of uniform compression of the charge in the cylinder under all speeds and under all conditions of fuel regulation. for uniform maintenance of the most effective colnpression. Thus. when the engine is running at high speed under light load (with the spark far advanced and the throttle partly closed), the auxiliary air passage is sufficiently opened to allow the engine to supplement the fuel supply with air drawn through the auxiliary air valve so that the volume of the charge may be substantially as great as that taken in when the engine is running under heavy load (with the throttle opened, the spark retracted. the air valve closed, and the entire charge taken through the carbureter). These coincident adjustments of the air-regulation valve and the spark-timing means tend to provide economical operation. At high speed under light load the fuel content of the charge is minimized and the spark far advanced. Under heavy load at high speed, when the throttle is widely opened` the tendency of the speed-responsive device to advance the spark is offset somewhat by the tendency of the throttle-controlled means to retract the spark and the air content of the charge is decreased. These automatic adjustments of the spark-timing and auxiliary air supply relate back to their initiation. directly or indirectly, to the throttle adjustment. and if desired, the throttle adjustment itself may be controlled by a speed-responsive device. operated by any part which it is desired to run by the engine at predetermined speed. Thus.

by associating with the engine shaft itself a speed governor controlling the throttle. uniform engine speed under varying loads. with the most economical operating conditions, may be. insured: or by association of such governor with the wheel shaftof a vehicle driven by the engine. predetermined vehicle speed may be. maintained with the fuel supply. the charge-regulator. and sparktiming adjustments. all automatically varied. for economical compensation for variations in the resistances met by the. vehicle in maintaining its predetermined speed.

Tn the drawings. wherein I have illustrated an embodiment of my invention. for the purposes of disclosure, Figure l shows in outline a `well known type of internal combustion engine. and a diagrammatic illustration of the application of devices thereto for the embodiment of my invention; Fig. 2 is a vertical cross section. on line :2 2 of Fig. 3. of a governor; Fig. 3 is a horizontal section on line 3 3 of Fig. 2; Fig. l is a detail of an auxiliaryT air-controlling valve; and Fig. 5 is a Schematic view of the regulator appliances.`

ln Fig. 1. 6 indicates in outline an engine of which T is the main shaft and 8 a driven counter shaft. 9 indicates the fuel-intake pipe. 10 a carbureter. 11 a throttle valve between the carbureter and engine intake port. and 12 a spark distributer. these parts being all conventionally shown.

15 indicates in general a speed-responsive device which in the specific embodiment shown (Figs. 2 and 3l comprises a main shaft 16. driven b v a miter gear 1T from the counter shaft S. and at its upper end. within a shell 1R. bearing a head 19. which supports a transverse shaft 19' having mounted thereon a heavy ring 20. so arranged that when the main shaft 16 is rotated. centrifugal action tends to swing the ring about its pivotal axis until it lies in approximately a horizontal plane. On the transverse shaft 19 are mounted two segluental gears 21 meshing with rack members Q2 guided by brackets 23 of the head 19 and cross connected by a transverse bracket 22. As the transverse shaft. 19 rocks. obviously. the racks will cause the bracket 22' to be raised and lowered.

ln direct alinement with the shaft 16 is a rod 25 having'ball bearing connection 26 with the bracket 22. and extending upward through a spring casing 2T. which is located in an extended neck 1S of the shell 1S. The rod 25 has fixed thereto a collar :29. which affords bearing for the governor spring 30.

abutting at its upper end against a follower S1. which loosely surrounds the rod 25. and has a sliding keyed connection 32 with the spring casing 2T to preventrotation of said follower.

)leans to regulate the biasing spring'resistance to the governor movement are provided as follows: The follower 31 has its upper edge formed into a crown cam 33 engaged by a similar cam 3-1 rotatable on the rod 25 and held in firm engagement with the cam 33 by a cap member 35 which is secured to the casing neck 1S. Beyond the cap member 35. the cam 34 has a lever arm extension 3T by which it may be rotatively moved. thereby to exert a cam action on the follower S1 to move it vertically and so to change the tension of the spring 30. This lever arm 3T has appropriate connection (Fig. 5) by a rod 3S with the fuel'control operating crank 11' for the throttle 11. so that as the crank 11 is rotated to open the throttle. crank 3T is rotated to increase the rod 25 rises.

tle is fully opened and' minimum spring re-V s istance when the throttle is closed.

At its projecting upper end. the rod 25 has connection with the horizontal arm of a bellcrank lever 40, suitably molmted on the engine. and the vertical arm of said lever is connected by a link-41 vto the relatively shiftable elelnent of the spark-distributer 1:2. in such fashion that the higher the end of the the farther the spark is advanced. (See Fig. 5).

Now. it will be apparent that as the speed of the engine increases or decreases. the action of the ring 20. commimicated through rod 25. 'tends to effect the spark distributer correspondingly to advance or to retract the spark. but the spring tension opposing the action of the ring is dependent upon the throttle condition. such spring tension increasing as the throttle is opened and decreasing as it closes. The desirability of these adjustments is apparent from a consideration of the conditions preliminarily discussed.

The auxiliary air-supply regulator may conveniently take the form of an air valve in the fuel conduit 9. having connection with the engine-speed-responsive device tobe automatically opened as the speed increases and moved toward closed position with decrease in speed'. It is my preference that the same speed-responsive device controlling the auxiliary air valve shall be subject to and modified b v throttle control. and therefore. I operate the air valve from the speed-responsive device 15 heretofore described. 51 indicates a link connection between the tail 50' of the valve 50 and the vertical arm of the bell crank lever 40. such connection causing the auxiliary valve to open wider as the bell crank is rocked by the governor in response to increase in speed modified by the throttle.

The throttle lever 11 may be provided with an operatingrod 55. leading to any suitable point of control. either manual or automatic. For some purposes, it is advantageous that the rod 55 be connected. for actuation. to a speed-responsive governor 56. driven by a suitable shaft 5T, the speed of which may accord with any suitable part driven by the engine.-either the engine shaft T itself or a traction wheel or shaft of the automobile.'` or the like. The governor 56 may have its spring abutment 58 shiftable manually as by the operation of cam 60 upon the stem 59 of said-abutment. the cam 60 being operable in an)7 suitable fashion from a remote point. and the arrangement shown being. of course. diagrammatic.l

It will be apparent. that with any given setting of the spring of governor 56, the 1atter will tend to maintain in the engine conditions producing such predetermined speed in said governor. As the resistance to the engine driven part actuating saidigovernor tends to decrease the governor speed, the governor tends to open the throttle for the production of an increase in fuel density, with a commensurate retraction of the spark, thereby to maintain the set speed. In versely, a Adecrease in the resistance to the engine-driven part, tends to increase the speed of the governor, but is met by a closing movement of the throttle with a commensurate spark advance ManieStly, in stationary engine Work` b v actuating governor 56 in harmony with the rotation of the engine shaft, substantially uniform speed may be maintained under varying load conditions through the operation of the governor 56; While in automobile practice, b v relating the governor 56 to a traction wheel or shaft, the governor will tend to produce in the engine at all times conditions resulting in the desired vehicle speed. Obviously', by manual control of the governor spring, variations in the predetermined set speed may be eected.

Itvvill non' be manifest that by proper adjustment of the spark time in accordance jointly with the throttle condition and the engine speed automatic adaptations in ignition timing compensating for variations in density, or density and. compression, of the charge are etfected,and that by suitable automatic adjustment oi the auxiliary air-supply valve, the compression. isv maintained approximately constant under varying conditions,-all to the end of accomplishing maximum Work with minimum .fuel by causing llame propagationto take place under Conditions 1S nearly as possible ideal.

What I claim'is:

1. The combinationwlthan internal combust-ion engine having regulable fuel-control means and sparking means, onf means including opposed regulable means and speed-responsive means anda vpart to be moved by the force of one said means over that exerted by the opposingmeans-.to'regulate the `tim` ing ot the spark in harmony jointly with the speed oit the engine and the position of the fuel-control-means Y 2. The combination-with an internal com-,-

bustion engine having'regulable fuel-control means Yand sparking means, of an enginespeed-responsivemeans, and means t vary the movement ofthe speed-responsive means at given speed in vharmony with. thefuel control means for afarying the spark-time controlled jointly bythe said speed-responsive means and the fuel-control means.

3. The combination with an internal combnstionvengine having regulable uel-control means and sparking means, means responsive to engine speed and vari-ably resisted in spark.

ineens? such response by the fuel-control means, and sparktiming means controlled by said speed-responsive means so governed.

4. The combination with an internal combustion engine having regulable fuel-control means and sparking means, means responsive to engine speed and variablyA modified in such response' by the yfuel control means, and spark-timing means controlled by said speed responsive means so modied.

5. The combination with an internal com bustion engine having regulable fuel-control means and sparking means. of an iengine-speed responsive means having an adjustable part, means connecting said speed responsive means and said spark-timing means, means connecting said adjustable part with the fuel-control :means fo'r adjusting the spark timing means in harmonyv with the condition of the fuel-control means and the speed responsive means.

y6. The combination. with an internal combustion engine having regulable fuel-control means and sparking means, of an engine-speed responsive means having a resistance-adjusting part, means connecting said rem'stance-adjusting part with the fuelcontrol means for adjustment in harmonyv with the condition of the fuel-control means, and spark-timing means controlled b v said speed-responsive means.

7. The combination with an internal combustion engine having regulable Jfuel-control A`when said fuel control means'is operated to' modify the operation of said speed responsive-means to control the relative time of the 9.'Tl1e combnationwith an internal comblstionengine having a regulable fuel-control means, of spark-timing means therefor,

and a differential governor having connectionsk vrespectively with the fuel-control means, an engine moved part, and said spark-timing means, for adjusting they timing means an amount determined by the speed of the engine varied bv an amount determined by the condition of the fuel-control means.

10. Anv apparatus for association with an internal combilstion'engine, a fuel throttle,

and spark-timer, comprising a part automatically movable by variation of engine operation for moving said spark-timer; a connection between said automatically movable part and said timer, including an adjustable part, and means movable in harmony with the throttle to adjust said part whereby to change the rate of movement of said timer,as the fuel charge, or load, is varied bysaid throttle.

`11. The combination with an internal combustion engine having regulable fuel control means, and a spark Vvarying means, of a spark-time controller comprising a part driven in time relation with the'engine; a biased part movable by variation of speed of said engine; variable means for opposing the movement of the latter part; a connection between the biased part and the sparkvarying means, and means operable when the fuel control means is operated for actuating said variable opposing mea-ns.

12. The combination vit-h an kinternal combustion engine, of spark-timing means,

el-control means, and an automatic governing device therefor including a movable part connected to said timing means, centrifugal means tending to move said part in one direction, and means, operated by said fuel-control means, for exerting an opposing tendency against the centrifugal means to render said centrifugal means subject to said fuel-control means.

13. The combination with an internal combustion engine, having regulable fuel control means and sparking means; of means, including opposed regulable means connected with the fuel control means and speed responsive means, and a part to be moved by the force of said speed-responsive means over that exerted by the opposing means to regulate the timing of the spark in harmony jointly with vthe speed of the engine and the position of the fuel control means. v

14. The combination with an internal combustion engine having a fuel-supply means and an auxiliary. alr-supply means, of means for regulatingthe auxiliary air supply including an engine-speed-responsive device, controlled by means for controlling theifuel supply means.

, 15. The combination with an internal combustion engine having a regulable fuelcntrol means and an auxiliary air-supply means, of means for regulating the auxlliary air-supply responsive jointly to the engine speed and the condition of the fuelsupply means. i

16. The combination with an internal combustion engine having regulable fuelcontrol means and spar g means. of means to regulate the timing of the spark in harmony with the fuel density of the compressed charge. and means to maintain constant compression of the charge under varying speeds. A.

17. The combination with' an internal combustion Vengine having vregulable fuel` control means and sparking means, of means to regulate the timing of the spark in harmony with the engine speed and the condition of the fuel-control means, and means to maintain constant compression of the charge under varying speeds.

18. The combination with an internal combustion engine having regulable fuelcont-rol means and sparking means and means to admit an auxiliary air supply governed jointly by the speed of the engine and said fuel control means.

19. The combination with an internal combustion engine having regulable fuelcontrol means and sparking means, of sparktiming means, auxiliary air-supply means, and an automatic-governing device, including a speed-responsive governor dominated by said fuel control means for varying the operation of the spark-timing means and auxiliary air-supply means.

20. The combination with an internal combustion engine having regulable fuelcontrol means-and sparking means. of sparktiming means, auxiliary air-supply means, an automatic governor device actuated by the engine and controlled accordingly to the condition of the fuel-supply means. means for control of said sparking means by said governor, and means for control of said auxiliary"air-'supply means by said governor, thereby to tend to preserve lmiformity in compression and to adjust the spark time to both engine Speed and fuel density.

21. The combination with an internal combustion engine having fuel-control means, of spark-timing means` automatic means to adjust the fuel-control means in harmony yvith the engine speed, and means to adjust the spark-timing means in harmony jointly with the condition of the f uel control means and the speed of the engine.

2:2. An apparatus for association with an internal combustion engine to automaticallycontrol the spark as the load varies, comprising a fuel throttle; a spark-timer; a part. movable by operation of the engine for moving the said timer. and means movable when said throttle is moved. to vary the rate of movement of said timer, when automatically moved by said engine movable part. v

23. The combination with an internal combustion engine having fuel control means and spark timing means. of means including a speed responsive device for adjusting the uel control means: means including an engine-speed-responsive device for adjusting the spark timing means: connections betiveen said speed responsive devices and means operable by first mentioned speed responsive device to modify the second mentioned speed responsive device in accordance with adjustment of said fuel control means.

2i. The combination with an internal combustion engine having fuel-control means. of spark-timing means, auxiliary airsupply means. means including a speed-responsive device for adjusting the fuel-control means. and means including an enginespeed-responsive device for adjusting the spark-timing and auxiliary air-supply means.

:25. The combination with an internal combustion engine of a carbureter; a fuel throttle for said carbureter; controlling means therefor: a spark-time controlling means: a speed-responsive means operated by said engine connected to said spark timing means. and a connection betvveen said. throttle controlling means and said speed responsive means adapted and arranged to modify the operation of said speed responsive means when said throttle is adjusted.

26. The combination vvith an internal combustion engine having a carbureter and regulable fuel control means therefor and variable sparking means, of an engine speed responsive means and'connections between said devices whereby to modify the action of said speed responsive means when the fuel admission opening of said carbureter is adjusted.

2T. The combination with an internal combustion engine, a carburetor; a controlling means therefor; a spark-time controlling means; a speed-responsive governor, and connecting means between said carbureter, controlling means and speed responsive governor, to modify the operation' of said governor when the fuel admission opening of said carburetor is adjusted.

28. The combination with an internal combustion engine,- a carbureter, a controlling means therefor, a spark-time controlling means. a centrifugal vernor, operated by the engine, and connecting means between said carbureter controlling means and said governor, to 'modify the operation 'of said i governor when the fuel admission opening of said carbureter is adjusted:

The combination with combustion engine, a carburetor having an auxiliary air-supply means, a fuel throttle, for said carburetor, controlling means therefor. a spark-time controlling meansfa centrifugal governor operated by said engine connected to said air-supply means and to said spark-timing means, and a connection betvveen said carburetor throttle-controlling means and said centrifugal governor adaptedand arranged to modify the operation of said governor when said throttle is adjusted.

30. The combination with an internal combustion engine having regulable fuelv an internal` insana? control means and sparking means, of sparktiming means, auxiliary-air-supply means, a part movable 1n joint response to changes 1n engine speed and fuel-control, and connections between saidfpart' and the spark-timing means and auxiliary air-supply means, respectively.

31. The combination with an internal combustion engine having regulable fuelcontrol means and sparking means, of sparktiming means, anengine-speed governor having connection to said spark-timing means, and connections between said fuel control means and said governor, to eect reduction or increase in the movement thereof, and, through the connections betvveen said governor and spark-timing means, in the spark-time forsaid combustion engine.

32. The combination with an internal combustion engine.. having regulable fuelcontrol means and sparking means, ofmeans responsive to engine speed and variably resisted in such response by the fuel control means. spark timing means controlled by said speed responsive means; a second engine speed responsive means operatively connected with the regulable fuel-control means and means for varying the resistance of the second :speed responsive means.

33. The. combination with an internal ASli combustion engine, having regulable fuel- 'means including opposed., regulable means connectedwith the fuel control means and d responsive means and a part to be moved by the force of said speed responsive means over that ekerted by the opposing means to regulate the timing of the spark in harmony jointly with the speed of the engine and the position of the fuel-control means; and an engine responsive means operatively connect with the regulable fuel control means.

35. The combination with an internal combustion engine, having regulable fuelcontrol means and sparking `means; of means including opposed regulable means connected with the fuel control means and speed responsive means and a part to be moved by the force of one said speed responsive means over that exerted by the opposing meanr., to regulate the timing of the spark in harmony vjointly with the speed of the engine and the position of the fuel con'- trol-means; an engine speed responsive means operatively connected with the regulable fuel control means; and means for var ving the lesistance of the last mentioned speed responsive means.

36. An apparatus for association with an internal combustion engine having a spark timer and an intake throttle comprising, a speed responsive member: a connection between said member and spark-timer vvhereby the time of ignition is varied by movement of the member and means associated vvith the throttle to modify the operation of said member for further affecting the time vof ignition.

3T. In combination, an internal combustion engine; av movable part, operable by the engine in. accordance `With varying conditions of engine operation; a fuel throttle: a spark-timer; connections between said timer and said engine-movable part for adjusting the spark-time, by movement of said part, and means connected for operation in harmony with throttle movement arranged to modify the action of said engine-movable part on said timer-to vary the rate of spark time adjustment vvhen said throttle is moved.

3S. In combination vvith an internal combustion engine; a movable part, operable by the engine in accordance with the conditions of engine operation: a fuel-throttle. for varying the volume of fuel charges: a sparktimer; connections between said timer and said engine-movable part, including an adjustable part to vary the ratio of movement of said timer, and means, operable in accordance vvith throttle movement,` to control said adjustable part to change the rate of movement of saidtimer in harmony with the conditions of fuel charge.

In testimony vvhereof I hereunto set my hand in the presence of tvvo Witnesses.

FREDERICK PURDY. In the presenceJ of` lV. LINN ALLEN, MARY F. ALLEN. 

